Evaluation of the electrical properties of dust storms by multi-parameter observations and theoretical calculations

Quantifying the large-scale electrification equilibrium effects in dust storms using field observations at Qingtu Lake Observatory

“…While water is not necessary for contact electrification (Baytekin et al, 2011a), a variety of studies indicated that such charge separation was strongly dependent 340 on the RH (Esposito et al, 2016;McCarty and Whitesides, 2008;Xie and Han, 2012;Zhang et al, 2017). The proposed reasons for this are twofold: On one hand, the presence of adsorbed water could increase surface conductivity and facilitate the ion or electron transfer (McCarty and Whitesides, 2008); On the other hand, OH − ions in adsorbed surface water could also act as charge carrier (Gu et al, 2013;Lacks and Sankaran, 2011;345 McCarty and Whitesides, 2008).…”

“…Theoretically, there is an electrification equilibrium effect (i.e., * is constant) if ρ and M 10 are linearly correlated at a given ambient temperature and RH (and 200 obviously, nonlinear relationship between them means time-varying * ). Since previous studies (Esposito et al, 2016;Harper and Dufek, 2016;Merrison, 2012;Wiles et al, 2007;Xie and Han, 2012;Zhang et al, 2017;Zheng et al, 2014) suggested that environmental factors such as ambient temperature and RH could considerably affect the intensity of Efields, SLR in this study were performed at a set of given temperature and RH intervals of where coefficient 0 is the fitted intercept, the fitted slope 1 is equal to * , and 1 is a disturbance term. We use the ordinary least squares method to estimate the coefficients of the SLR model (Eq.…”

“…Previous studies are mainly concerned with the vertical profile of E-fields in the near-ground region and their influence on dust transport (e.g., Esposito et al, 2016;Kamra, 1972;Rudge, 1913;Yair et al, 2016). The measurements showed that the vertical E-fields decrease with increasing height in the sub-meter region (e.g., Schmidt et al, 1998), but exhibit multi-layer 65 properties in the region of up to 30 m height (Zhang et al, 2017). Though measurements of E-fields in dust events are numerous, the measurements associated with the electrical properties of dust particles are relatively sparse.…”

“…Additionally, preliminary research (Esposito et al, 2016;Merrison, 2012;Xie and Han, 85 2012; Zhang et al, 2017;Zheng et al, 2014) suggests that environmental factors such as the ambient temperature and RH could considerably affect the intensity of E-fields. nt is still unknown whether environmental factors have an impact on the properties of dust electrification, and especially electrification equilibrium effects in a dust storm.…”

“…More detailed information of the VREFM is given in our previous works (see Zhang et al, 2017;Zheng, 2013). The partial derivatives of E-fields were estimated from the interpolation-based numerical method and will be shown to be both positive and negative (see Fig.…”